Figure 2. Ars2 genetic deletion causes proliferative arrest and bone marrow hypoplasia.
A) Ars2flox/flox (fl) and wild-type (wt) control MEFs were infected with retrovirus expressing Cre recombinase and expanded for 72 hours and then protein extracts were analyzed by Western blot.
B) Wt and fl MEFs were infected with retroviral Cre as in (A). Between 72 and 120 hours after infection population doublings were measured by modified 3T3 assay. The data presented are the mean ± SD of triplicate samples.
C) In vivo deletion of Ars2 was achieved by injection of 6–8 week-old mice with polyinosinic-polycytidylic acid (pIpC) every other day over a two week period. Mice bearing one floxed allele of Ars2 (fl) and one null allele (−) (fl/−) were crossed to mice harboring an MxCre transgene to create mice with the compound genotype fl/−; MxCre. Controls included mice of the genotypes fl/wt and fl/wt; MxCre. The mice were sacrificed 9 days after the last injection and tissues (spleen, liver) were harvested for protein extraction. Ars2 levels were determined by Western blot.
D) pIpC injection was performed as in (C) and mice were sacrificed 9 days following the last pIpC injection. Liver and bone marrow were harvested and histological staining was performed with hematoxylin and eosin.